Error X-OWA-Error: SDServerErr;Microsoft.Exchange.Services.Core.Types.MissingEmailAddressForDistinguishedFolderException

After you recently mailenabled a user and log in to the web interface, it throws (amongs others) this error message:

X-OWA-Error: SDServerErr;Microsoft.Exchange.Services.Core.Types.MissingEmailAddressForDistinguishedFolderException

Just sit back a couple of minutes and let stuff replicate and try again.